Lucy gave birth to her daughter Rosie five months ago, and claims it took her just two months to shed the two stone she put on.
Flaunting her new bod in a blue bikini for a photo-shoot for Closer magazine, five-foot tall Lucy says she has dropped from 9st 5lb to 7st 6lb.
The 41-year-old told the magazine: 'I convinced myself that it would be much harder to lose weight because of my age, but I'm surprised at how quick and easy it was.'
She says the catalyst for losing weight came about when her four-year-old daughter Bessie looked at her tummy on holiday and asked her if she was having another baby.
The full story appears in this week's Closer magazine, out now.
WHY do celebs have to do this? No matter how good they look, does anyone really want to see them in a bikini boasting about their weight loss? What kind of message does it send out to 'normal' mums?
What do you think?